39 research outputs found

    Effectiveness of Isolated vs. Integrated Form-Focused Instruction in Iranian EFL Classrooms

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    The present study investigated the effectiveness of integrated form-focused instruction (FFI) vs. isolated FFI on certain target structures, namely passives and condition type two. Three experienced female teachers taught 60 EFL learners in two experimental groups receiving isolated and integrated FFI treatment packages and in one control group for 12 sessions. The treatment in the integrated group included the use of videos, games, free discussions, essay writing, and readings with follow-up questions. After homogenizing the participants through a proficiency test, all of them were briefed on the concept of integrated and isolated FFIs and experienced this type of instruction through some concrete tasks on one grammatical structure. Similarly, the teachers were briefed on these two types of FFIs and practiced micro-teaching of one grammatical structure. Parallel pre- and post-tests in the form of recognition and production types were administered to all three groups in order to measure the effectiveness of the two treatments. The findings manifested the learners in both treatment groups outperformed their counterparts in the control group. Moreover, there was a statistically significant difference between the two experimental groups, and integrated group learners achieved the highest scores in both production and recognition tests. This study advocates more incorporation of integrated FFI and supports the notion that it could lead to a higher rate of meaning-oriented learner-generated output along with effective internalization of grammatical structures in EFL classes

    The Effects of Different Ionic Liquid Coatings and the Length of Alkyl Chain on Antimicrobial and Cytotoxic Properties of Silver Nanoparticles

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    Introduction: The antibacterial efficacy and toxicity of silver nanoparticles (AgNPs) depends on their physicochemical properties including size, shape, surface charge and surface coatings. The Objectives of this study were: i) To synthesize and characterize positively charged AgNPs coated by different ionic-liquids with different alkyl chain lengths, ii) To evaluate the antimicrobial activity of these nanoparticles against Enterococcus faecalis compared to sodium hypochlorite (NaOCl) and chlorhexidine (CHX), iii) To compare the cytocompatibility of these solutions against L929 mouse fibroblasts. Methods and Materials: AgNPs with positive surface charges capped by two different ionic liquids [imidazolium (Im) and pyridinium (Py)] with two alkyl chain lengths (C12 and C18) were synthesized. Im and Py were also tested as control groups. The characterization revealed synthesis of spherical NPs in the size range of 6.7-18.5 nm with a surface charge ranging from +25 to +58 mV. To standardize the comparisons, the surface charge to radius ratio of each nanoparticle was calculated. The minimum inhibitory concentrations (MIC) of the AgNP solutions, NaOCl and CHX were determined against E. faecalis by a microdilution test. An MTT-based cytotoxicity assay evaluated the cytotoxicity of the solutions in different concentrations on L929 fibroblasts. One-way and two-way ANOVA were used for statistical analysis. Results: All tested AgNPs reached MIC90 in significantly lower concentrations compared to CHX and NaOCl. C12 Py-coated AgNPs had the lowest MIC90 value. CHX and NaOCl were more toxic on fibroblasts than all tested AgNPs. Im-coated AgNPs had better compatibility with fibroblasts than Py-coated particles; and C12 Im AgNPs had the best biocompatibility. Variations in alkyl chain length had no effects on the biocompatibility of AgNPs. Conclusion: Py improved the antibacterial efficacy of AgNPs compared to Im; however, it had a negative effect on cytocompatibility. Alkyl chain length had no effects on AgNPs’ bioactivity.Keywords: Antibacterial Agents; Chlorhexidine; Cytotoxicity; Metal Nanoparticles; Sodium Hypochlorit

    Molecular Genotyping of the Human Cystic Echinococcosis in Mazandaran Province, North of Iran

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    Background: The larval stage of the tapeworm (cestode) Echinococcus granulosus is the etiological agent of hydatidosis or cystic echinococcosis, which is the zoonotic parasitic disease causing morbidity and mortality in both humans and livestock. Due to a lack of accurate data on the human isolates of E. granulosus in Mazandaran Province, northern Iran, the current study aimed to survey the population genetic pattern of cystic echinococcosis isolated from humans by sequencing the mitochondrial genes of NADH dehydrogenase subunit 1 (nad1). Methods: Overall, 47 formalin fixed paraffin-embedded tissue (FFPT) blocks were collected from patients' files in various pathology departments of Mazandaran Province in Iran from 2003 to 2015. PCR was performed to amplify a 398bp DNA fragment of mitochondrial nad1. PCR products were sequenced by Bioneer Corporation (South Korea), and the resulting data were analyzed via relevant software to determine the genotypes. Results: The nad1 gene was successfully amplified on 10 from all of the E. granulosus isolates. Overall, 66.6% and 33.3% of the isolates in the studied area displayed the G1 and G2-G3 genotypes, respectively. Conclusion: This study may provide the foundation for further studies in revealing the regional transmission patterns and also in designing adequate control procedures

    Freshwater snails as the intermediate host of trematodes in Iran: a systematic review

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    Freshwater snails, as the first intermediate hosts of trematodes, can cause health hazards in animals and humans. Recently, the World Health Organization has included Iran in a list of 6 countries known to have serious problems with fascioliasis. In addition, cercarial dermatitis is a job-related disease that is seen often in paddy workers, agricultural labourers, and fishermen in Iran, particularly in Mazandaran Province. Many studies have been conducted in Iran to survey larval trematodes in freshwater snails. However, to the best of our knowledge, no comprehensive data exist regarding infections in gastropods. Therefore, the aim of the present study was to estimate the types and prevalence of cercarial infections in snails in Iran. Electronic English-language and Persian-language databases were searched to identify 24 published articles reporting the prevalence of trematode infections in snails (9 species from 6 families) in various provinces of Iran. In total, 4.4% of gastropods were infected with the larval stages of trematodes. According to the studies reviewed in this meta-analysis‚ the highest infection prevalence was found in Radix auricularia (9.9%). Twelve larval species of trematodes were identified, and the highest prevalence of cercariae was found for Echinostomatidae cercariae (4.3%). Among the provinces explored, West Azerbaijan had the highest prevalence of infected snails (16.9%). The presence of trematodes in snails could pose a serious health problem in Iran. Thus, further studies are necessary to characterize these infections in other provinces

    The Effect of Charge at the Surface of Silver Nanoparticles on Antimicrobial Activity against Gram-Positive and Gram-Negative Bacteria: A Preliminary Study

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    The bactericidal efficiency of various positively and negatively charged silver nanoparticles has been extensively evaluated in literature, but there is no report on efficacy of neutrally charged silver nanoparticles. The goal of this study is to evaluate the role of electrical charge at the surface of silver nanoparticles on antibacterial activity against a panel of microorganisms. Three different silver nanoparticles were synthesized by different methods, providing three different electrical surface charges (positive, neutral, and negative). The antibacterial activity of these nanoparticles was tested against gram-positive (i.e., Staphylococcus aureus, Streptococcus mutans, and Streptococcus pyogenes) and gram-negative (i.e., Escherichia coli and Proteus vulgaris) bacteria. Well diffusion and micro-dilution tests were used to evaluate the bactericidal activity of the nanoparticles. According to the obtained results, the positively-charged silver nanoparticles showed the highest bactericidal activity against all microorganisms tested. The negatively charged silver nanoparticles had the least and the neutral nanoparticles had intermediate antibacterial activity. The most resistant bacteria were Proteus vulgaris. We found that the surface charge of the silver nanoparticles was a significant factor affecting bactericidal activity on these surfaces. Although the positively charged nanoparticles showed the highest level of effectiveness against the organisms tested, the neutrally charged particles were also potent against most bacterial species

    Light-Powered Reactivation of Flagella and Contraction of Microtubule Networks: Toward Building an Artificial Cell

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    Artificial systems capable of self-sustained movement with self-sufficient energy are of high interest with respect to the development of many challenging applications, including medical treatments, but also technical applications. The bottom-up assembly of such systems in the context of synthetic biology is still a challenging task. In this work, we demonstrate the biocompatibility and efficiency of an artificial light-driven energy module and a motility functional unit by integrating light-switchable photosynthetic vesicles with demembranated flagella. The flagellar propulsion is coupled to the beating frequency, and dynamic ATP synthesis in response to illumination allows us to control beating frequency of flagella in a light-dependent manner. In addition, we verified the functionality of light-powered synthetic vesicles in in vitro motility assays by encapsulating microtubules assembled with force-generating kinesin-1 motors and the energy module to investigate the dynamics of a contractile filamentous network in cell-like compartments by optical stimulation. Integration of this photosynthetic system with various biological building blocks such as cytoskeletal filaments and molecular motors may contribute to the bottom-up synthesis of artificial cells that are able to undergo motor-driven morphological deformations and exhibit directional motion in a light-controllable fashion.R.A., V.N., E.B., I.G., and A.G. acknowledge support from the European Union’s Horizon 2020 research and innovation programme under grant agreement MAMI No. 766007. C.K., A.B., E.B., K.S., I.G., T.V.K., and A.G. thank MaxSynBio Consortium, which is jointly funded by the Federal Ministry of Education and Research of Germany and the Max Planck Societ

    BIOTECHNOLOGICAL PRODUCTS AND PROCESS ENGINEERING EGFP reporter protein: its immunogenicity in Leishmania-infected BALB/c mice

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    Abstract Optical reporter genes such as green fluorescent protein (GFP) and luciferase are efficiently and widely used in monitoring and studying the protective/therapeutic potential of candidate agents in leishmaniasis. But several observations and controversial reports have generated a main concern, whether enhanced GFP (EGFP) affects immune response. To address this issue, we studied the immunogenicity of EGFP in vivo by two lines of stably transfected parasites (Leishmania major EGFP or L. major EGFP-LUC ) in BALB/c model and/or as a recombinant protein (rEGFP) produced in vitro by bacteria in parallel. Disease progression was followed by footpad swelling measurements and parasite burden in draining lymph nodes using microtitration assay and real-time PCR, and immune responses were also evaluated in spleen. EGFP-expressing parasites generated larger swellings in comparison with wild-type (L. major) while mice immunized with rEGFP and challenged with wild-type parasite were quite comparable in footpad swelling with control group without significant difference. However, both conventional and molecular approaches revealed no significant difference in parasite load between different groups. More importantly, no significant inflammatory responses were detected in groups with higher swelling size measured by interferon-Îł (IFN-Îł), interleukin (IL)-10, IL-5, and nitric oxide against frozen and thawed lysate of parasite as stimulator. Altogether, these results clearly revealed that EGFP protein expressed in prokaryotic and eukaryotic hosts is not an immunological reactive molecule and acts as a neutral protein without any side effects in mice. So, EGFP expressing Leishmania could be a safe and reliable substitution for wildtypes that simplifies in situ follow-up and eliminates the animal scarification wherever needed during the study

    Parasitic Helminths in Wild Boars (Sus scrofa) in Mazandaran Province, Northern Iran

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    Background: Wild boars (Sus scrofa) are distributed worldwide and found in many parts of Iran. Although S. scrofa is reservoirs for many parasites, there is little data on helminthic prevalence in them. We aimed to survey the status of helminthic infections in S. scrofa in the Mazandaran Province of northern Iran. Methods: Twenty-one wild boars were captured and examined for helminth infection during Dec 2012-Mar 2014. Adult worms such as Macracanthorhynchus hirudinaceus were identified by helminth size and shape, and the arrangement of the proboscis hooks. The sedimentation and flotation techniques were used to detect parasite eggs and larvae in faecal samples. Muscle samples were also surveyed for Trichinella larvae by artificial digestion method. Results: Of the 21 samples, 13 (61.9%) were infected with one or more helminth species. Seven helminth types were identified in the alimentary track, comprising 5 nematodes, 1 trematode, and 1 acanthocephalan, with prevalence rates of Macracanthorhynchus hirudinaceus (57.14%), Globocephalus spp. (33.33%), Trichuris suis (19.04), Gongylonema pulchrum (14.28%), Fasciola hepatica (14.28%), Dioctophyma renale (4.76%), and Ascaris suum (4.76%). Conclusion: Wild boars might be involved in transmitting zoonotic parasites to humans. The abundance of these animals near human habitation creates favorable conditions for infection. So the risk of parasitic helminth diseases increases in other animals and humans

    The Role of Worry, Hope and Meaning of Life in Predicting Mental Health of Mothers with Mental Disabled Children

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    This study was performed aimed to investigate the role of worry, hope and meaning of life in predicting mental health of mothers whose children were mentally disabled. The study method was descriptive and correlational. all the mothers with mental-disabled children under rehabilitation centers of welfare organization in the city of Ardabil in 2015-2016 formed the population of this study that Among them using available sampling method, 130 mothers were selected and responded to Pennsylvania worry questionnaire, Schneider adult hope questionnaire, Grumbaugh and Maholick purpose in life questionnaire and Goldberg and Hiller general health questionnaire. To analyze the data, tests of Pearson correlation coefficient and multiple regression analysis were used. Results showed that there is a negative significant relationship between worry and its components with mental health of mothers with mental-disabled children and also there is a positive significant relationship between hope and meaning of life with mental health of mothers whose children were mentally disabled (p<0.01). Also, Results of regression analysis revealed that 0.58 percent of the total mental health variance of women with mental- disabled children was predictable based on variables of worry, hope and meaning of life. Therefore, it can be concluded that the worry, hope and meaning of life are the related variables with the mental health of mothers whose children were mentally disabled. So it can be concluded that worry, hope and meaning of life are the variables that associated with mental health of mothers whose children were mentally disabled which need planning

    The Effect of Osteoporosis Prevention Education on Knowledge, Attitude and Behavior of Adolescent Female Students in Kermanshah, Iran

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    Background and Objectives: Osteoporosis is a common metabolic bone disorder among females. Primary prevention is the easiest and cheapest way to deal with this condition. Therefore, it is important to educate about osteoporosis risk factors and preventive behaviors during adolescence. This study aimed to evaluate the effect of osteoporosis prevention education on knowledge, attitude and practice of adolescent female students in Kermanshah, Iran. Materials and Methods: We performed this quasi-experimental research in 118 adolescent female students in Kermanshah in 2014. The participants were selected with multistage cluster sampling form guidance schools of the city. They were allocated randomly to intervention (n=53) and control (n=65) groups. We collected data by a four-part questionnaire including demographic information, knowledge, attitude and behavior about osteoporosis prevention. Data were analyzed in SPSS 19 using independent t-test, paired t-test, chi-squared and Pearson’s correlation. Results: The mean scores of knowledge, attitude and practice displayed no significant difference between case and control groups at pre-intervention (P>0.05). However, the averages of knowledge (P=0.024) and attitude (P=0.003) increased significantly in the training group after performing the educational program. Although, the behavior mean had no significant difference between the two groups at post-intervention (P= 0.086). Conclusions: Educating about osteoporosis prevention led to promote the knowledge and attitude of adolescent female students in Kermanshah. However, this training had no influence on behavior. It is necessary to consider this problem in designing educational interventions in this target group
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